<template>

  <div class="app-container">
    <mt-header class="nav-header" fixed title="Home">
      <span slot="left" @click="goBack" v-show="flag">
        <mt-button icon="back">返回</mt-button>
      </span>
    </mt-header>

    <transition>
      <router-view></router-view>
    </transition>

    <!-- tabbar区域 -->
    <nav class="mui-bar mui-bar-tab">
      <router-link class="my-tab-item" to="/home">
        <span class="mui-icon mui-icon-home"></span>
        <span class="mui-tab-label">首页</span>
      </router-link>
      <router-link class="my-tab-item" to="/member">
        <span class="mui-icon mui-icon-contact"></span>
        <span class="mui-tab-label">会员</span>
      </router-link>
      <router-link class="my-tab-item" to="/shopcar">
        <span class="mui-icon mui-icon-extra mui-icon-extra-cart"><span class="mui-badge" id="badge">{{totalcount}}</span></span>
        <span class="mui-tab-label">购物车</span>
      </router-link>
      <router-link class="my-tab-item" to="/search">
        <span class="mui-icon mui-icon-search"></span>
        <span class="mui-tab-label">搜索</span>
      </router-link>
    </nav>
  </div>
</template>

<script>
import {mapGetters} from "vuex" 
  export default {
    data() {
      return{
        flag: true
      }
    },
    methods: {
      goBack() {
        //点击返回按钮，向后跳转
        this.$router.go(-1);
      }
    },
    created(){
       if (this.$route.path === '/home') {
          this.flag = false;
        } else {
          this.flag = true;
        }
    },
    watch: {
      //当页面刷新的时候，不会触发watch中监听的路由地址的变化
      "$route.path": function (newVal, oldVal) { //用watch监听的函数中有2个值
        if (newVal === '/home') {
          this.flag = false;
        } else {
          this.flag = true;
        }
      }
    },
    computed:{
      ...mapGetters(["totalcount"])
    }
  }
</script>


<style scoped>
  h3 {
    color: red;
  }

  .app-container {
    padding-top: 40px;
    padding-bottom: 50px;
    overflow: hidden;
  }

  .nav-header {
    z-index: 999;
  }

  .v-enter {
    opacity: 0;
    transform: translateX(100%);
  }

  .v-leave-to {
    opacity: 0;
    transform: translateX(100%);
    position: absolute
  }

  .v-enter-active,
  .v-leave-active {
    transition: all 0.4s ease;
  }

  .mui-bar-tab .my-tab-item.mui-active {
    color: #007aff;
  }

  .mui-bar-tab .my-tab-item {
    display: table-cell;
    overflow: hidden;
    width: 1%;
    height: 50px;
    text-align: center;
    vertical-align: middle;
    white-space: nowrap;
    text-overflow: ellipsis;
    color: #929292;
  }

  .mui-bar-tab .my-tab-item .mui-icon {
    top: 3px;
    width: 24px;
    height: 24px;
    padding-top: 0;
    padding-bottom: 0;
  }

  .mui-bar-tab .my-tab-item .mui-icon~.mui-tab-label {
    font-size: 11px;
    display: block;
    overflow: hidden;
    text-overflow: ellipsis;
  }
</style>